In most DC electrical power systems for automotive, aerospace and stationary applications, the electrical power requirements have been increasing dramatically over the last several years. There is an ongoing trend to move to a 42-volt power system which is now being deployed in the automobile industry in order to meet the increased electrical parasitic loads. The increasing use of electrical systems in automobiles and aircraft is driven by the introduction of new functionality which will be provided by these systems, and an inherently higher level of control when engine-driven loads are replaced with electrically-powered versions.
One arrangement for addressing this rise in electrical power requirements uses direct energy converters (DECs) to recover heat and waste energy and augment the current power plants in vehicles. DECs provide electrical power over an extremely broad range of voltages, nominally 1 mV to several volts DC, but are typically stacked up in series to provide voltages in excess of 300 volts DC. The load currents typically range from 1 milliamp to 300 amps DC, as the power demand in DC electrical systems can vary widely depending upon the mode of operation and upon parasitic subsystems which randomly come on line.
If as stated above, DECs are utilized to augment the engine or power-plant, and as such, improve their overall efficiency, it is further desirable that the energy converter itself be optimized to operate at high efficiencies. The proposed system is introduced in order to provide a control scheme (hardware and software) necessary to achieve these higher efficiencies. In addition, the proposed system could also be used to optimize or maximize the lifetime and stability of the DEC energy source.